Measuring Apparatus Positioning Error Compensation
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Solution Overview
Problem
In measuring apparatuses, deviations in measurement values occur due to non-ideal positioning between the sensor unit and the object, affecting measurement accuracy.
Innovation Solution
A measuring apparatus with a sensor unit and positioning device that moves along a guide, using a matrix sensor to detect measurement points and account for periodic position deviations through a positioning characteristic, allowing for accurate measurement value determination by averaging sensor signals across multiple positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a positioning device moves the sensor unit along a guide to measure multiple points, then measurement coverage and productivity are improved, but periodic position deviations occur due to non-ideal positioning, worsening measurement precision
Solution Approach 1:
The control device determines actual positions of the sensor unit using a position sensor and scale, compares these with target positions, and uses the deviations to correct measurement values. This feedback loop compensates for periodic positioning errors while maintaining continuous movement for high productivity.
Solution Approach 2:
The system changes the measurement approach by averaging sensor signals at multiple measurement points around the periodic deviation pattern. By collecting data at different positions and combining them with appropriate weighting, the system eliminates the periodic error component while preserving the actual measurement information.
2Measurement precision
If the sensor unit is positioned precisely at each measurement point, then measurement precision is improved, but the complexity of the positioning device and time required increase, worsening ease of operation
Solution Approach 1:
The system uses the periodic nature of the positioning errors to its advantage. By automatically measuring at multiple points and using the known periodic pattern to weight and average the results, the system self-corrects without requiring complex active compensation mechanisms or manual intervention.
Solution Approach 2:
The system exploits the periodic pattern of positioning deviations by measuring at multiple points that span complete periods of the deviation pattern. This allows the periodic errors to cancel out when measurements are properly averaged, transforming a repeating error into a correction opportunity.
3Productivity
If multiple measurement points are measured concurrently to improve productivity, then productivity is improved, but determining the correct measurement value becomes more difficult due to positioning deviations, worsening measurement precision
Solution Approach 1:
The system measures at more measurement points than the minimum single point, collecting excessive data that includes redundant measurements. By averaging these multiple measurements with appropriate weighting based on their positions relative to the periodic deviation pattern, the system extracts the true value while eliminating error components.
Solution Approach 2:
The control device determines the actual positions of the sensor unit before using the sensor signals for measurement. This preliminary position determination allows the system to apply correct weighting factors to each measurement based on the known periodic deviation pattern, ensuring accurate value determination even with concurrent measurements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly enhances measurement accuracy by compensating for positioning errors and periodic deviations, resulting in precise determination of measurement values with minimal influence from positioning fuzziness.
Implementation Method 1
DE 197 21 915 C1 describes a method for measurement of unevenness formed by ripples or long undulations, of a rail along which the sensor unit is moved. For this purpose, a light line is directed in extension direction of the rail on its surface and the reflection of light is detected.
Data Source
AI summary
A measuring apparatus and a method for determination of a measurement value of an object are disclosed. A sensor unit, produces one sensor signal respectively in different measuring positions along a positioning direction for multiple measurement points on an object, wherein the sensor signal describes the position of the measurement point. A positioning device positions the sensor unit and the object in the different measuring positions relative to one another in a positioning direction. The positioning or relative movement in the positioning direction is influenced by a periodic position deviation of the positioning device, which influences the detected sensor signals of the measurement points. A positioning characteristic describing the wavelength and/or the period of the periodic position deviation is determined. By means of the positioning characteristic, the sensor signals obtained for multiple measurement points in different measuring positions can be corrected to obtain the measurement value for the respective measurement point therefrom.